Labview与SR23岛电调节器的Modbus通讯方法

以《工业热电偶计量检定装置研究》项目实例为对象,通过计算机上的RS232串行通讯接口与岛电SR23调节器的RS485通讯接口及MAX202E线驱动/接收器、MAX3080串行通信转换成RS485总线芯片为硬件平台,利用Labview与MODBUS通讯协议为软件平台,根据岛电SR23调节器Modbus协议从设备功能吗、主从设备数据响应格式和Labview的配置串口、数据写入、数据读取、设备关闭等函数,详细阐述了通过Labview软件平台读取岛电SR23调节器实时值、设定值、输出值、比例度等参数的方法。实现岛电SR23调节器参数集中管理,可视的操作界面。

日本岛电SD20系列数字显示仪电源检修

本文简要介绍日本岛电SD20系列数字显示仪电源原理与典型故障维修,并根据实际情况提出完善措施。

非电行业大型输煤、锅炉岛消防设计介绍

随着我国工业化进程的不断推进,大型贮煤输煤设施及锅炉也在非火电行业得到应用。本文结合非电力行业的北方某化工厂输煤岛、锅炉岛工程项目,对其执行的设计标准、固定消防系统设计的重点、难点问题进行了介绍。

基于三菱FX_(2N)_PLC及SR93温控仪的自动烘干线改造

岛电通讯协议是日本岛电公司自定义的ASCII码通讯协议,在通讯发送及应答的数据中都是ASCII码。在本文中笔者将介绍金属喷涂件自动烘干线改造中三菱FX2N_PLC与岛电SR93温控仪进行岛电通讯协议的通讯控制方式。并具体说明如何通过三菱FX2N_PLC编程,实现利用FX2N-485-BD通讯模块对温控仪测量值进行采集的方法。同时在三菱FX2N_PLC中增加温度测量值判断程序,达到自动烘干线的改造要求。

Foraging areas of Rousettus leschenaulti on the Hainan Island of China

We investigated the foraging area of three individuals (1 female and 2 males) of Rousettus leschenaulti (Chiroptera,Pteropodidae) in suburban Haikou City, Hainan Province, South China from November 2005 to January 2006 using radio telemetry.These animals left the daytime roosting sites about 90 min after sunset with no significant difference in departure time betweenthe male and female bats. The average active times were 391.8 min for males and 533.7 min for the female, respectively.By reconstructing 93 radio-telemetry recording positions, we found that the long axis of foraging area of the bats ranged from7.45 to 11.70 km. The foraging area of the female (3867 ha) was larger than that of the males (1138 ha), and there was overlapbetween the foraging areas of different individuals. These bats usually kept the same flight routes across a few successive daysfrom the daytime roosting site to the foraging areas. Our findings suggested that female R. leschenaulti may explore a larger foragingarea than males. No obvious territorial behaviors were observed in our studied area.

An insulinoma with clinical and electroencephalographic features resembling complex partial seizures

We described a female patient with insulinoma who experienced recurrent episodes of automatism, confusion and convulsion. Furthermore, her electroencephalography （EEG） findings resembled the pattern in complex partial seizures with secondary generalization. The interictal EEG showed spikes and sharp waves, as well as focal slowing over the left temporal lobe, and the ictal EEG revealed generalized spikes and sharp waves associated with diffused slowing. She was initially misdiagnosed as pharmacoresistant epilepsy. After the insulinoma was found and surgically removed, her EEG turned normal and she was seizure-free during the 4-year follow-up. This report highlights the need for careful reassessment of all seizures refractory to medication, even for the oatients associated with eoileotiform discharges on EEG.

FRT Control Method Including Islanding Detection in PCS Model for Photovoltaic Generation

The experimental results by the simulated PV （photovoltaic） system for understanding the cause of disconnection when instantaneous voltage sag occurs are reported in this study. Moreover, it is understood that the PCS with the voltage phase jump detection method which is one of the main causes of the disconnection. We modeled it in the simulation. When fault occurs, even though the residual voltage is more than 20% and the voltage sag time is within 1.0 s, the PCS disconnected by the voltage phase jump detection was confirmed in the simulation results. Ifa large number of PV systems are interconnected in the power system, this study is verified through the simulation that the interaction caused by the disconnection which generated by the voltage phase jump detection. This study is proposed threshold limit value of islanding detection. The validity of proposed method was verified through the simulation in this study.

An Advanced Teaching Lab for the Setting up of an Islanded Production Unit

The present paper addresses an advanced teaching lab consisting of setting up an islanded production unit. This teaching lab takes place in the very last semester at master level for students in electrical engineering with energy specialization. The purpose of this teaching lab is to combine knowledge learned in different areas such as power electronics, control, electrical machines and networks, and make use of all of them in practice. The present paper describes in detail the different steps followed by the student to set up an islanded production unit.

Vector Shift Method for Islanding Detection Based on Simulation Test

Vector shift(VS)is one of the typical methods used for islanding detection in distributed generations.This paper investigates the impact of both the active power imbalance and load variation on VS method.The investigation was conducted via simulation test in the power system dynamic simulation laboratory of Shandong University.The results show that it will take longer time for the VS relay to detect islanding state with the decrease of active power imbalance.In some cases,the vector shift angle is smaller than the setting and VS method would not be able to detect islanding state.In addition,the performance of VS method is impacted by the load variation in normal operation in which the distributed generator is operated in parallel with the main grid.The simulation results show that VS method would cause nuisance tripping if the load changes sharply. It can be summarized that VS method would be unable to reliably discriminate islanding state and normal system disturbances in some cases.

Innovative Control Strategy for Islanded Small Hydro Power Plant

In many developing countries, there are regions where the electrical grid is weak or nonexistent. However, in these areas, large amounts of distributed energy sources, such as hydro, are often available and could be suitably exploited. To this aim, the low head hydro power plants can play a significant role. In fact, recent technological advances in mini-hydro turbines and decreasing costs of static electricity conversion devices enable to realize suitable power plants for an efficient and profitable exploitation of these sites. One of the major challenges is the integration of the above-mentioned power plants into autonomous electrical systems, islanded and/or disconnectable from the main distribution network. In this paper, an innovative control strategy for a low head hydro power plant supplying users in small clusters of villages is proposed.

Stability Study of a Mixed Islanded Power Network

This paper presents the modelling, simulation and analysis of the dynamic behaviour of a mixed power network of 2.78 GW including hydro, thermal and wind power plants. The modelling of each power plant is described. The set of parameters of the turbine speed governor of the hydroelectric power plant is determined with a specific identification procedure to achieve stable operation for different cases such as interconnected, isolated or islanded operation. The analysis of the stability of the entire mixed islanded power plant is investigated through time domain simulations for different sets of controllers parameters and for different disturbances （load rejection and turbulent wind speed profile）.

Study of Microturbine Models in Islanded and Grid-Connected Mode

Modeling and simulation of two different microturbine （MT） models to analyze load following performance as distributed energy resource （DER） have been presented in this paper. The first model consists of speed governor, acceleration control, and temperature control blocks while the other is GAST model. The system comprises a synchronous generator and a MT coupled to it. Simulations are carried out in islanded and grid-connected mode to observe the system response when supplying variable loads. The load following characteristics is observed and validated for this MT-synchronous generator model in Matlab-Simulink environment. This is applicable with combined heat power （CHP） generators both with general fuel as well as bio-fuels. The use of bio-fuels is very much promising for generating green power preventing green house gas emissions for fighting against global warming.

Utilization of DFIG on an Islanded Power Generation and Distribution System

The utilization of wind generation equipment, such as DFIGs （double fed induction generators）, interconnected to islanded power generation and distribution systems is investigated in order to determine their effects on the overall system operating characteristics and stability. The use of a stable power station （with high speed machines） will be critical in achieving fast and reliable transient response to network events, in particular, when large transient loads are expected on a continuous basis, i.e., industrial mining and mineral processing equipment. Simulation results of this paper assist in understanding how small power stations and wind generation equipment respond to large transients in an islanded network. In particular, detailed simulations and analyses will be presented on impacts of distributed wind generation units （1.5 MW DF1G） on the stability of a small weak network. The novelty of this paper is on detailed analyses and simulation of weak networks with interconnects DFIG＇s including their impacts on system stability under various transient operating conditions.

Reliability Optimization in the Islanded Mode of Microgrid

A microgrid is a combination of distributed energy resources and controllable loads. The main objective of this research is to optimize energy flow within a microgrid with regards to reliability in grid connected mode. A microgrid with combined heat and power, natural gas generator, diesel generator, solar energy, wind energy, and battery energy storage along with a critical load is considered in this research. An event oriented analytical method called FTA （fault trees analysis） is implemented for reliability optimization using PTC Windchill Solutions software in a microgrid. The reliability of each component in each energy source of the microgrid is calculated using FTA. The reliability of the critical load is evaluated. The quantitative and qualitative results of FTA are evaluated in order to interpret the results of fault tree. The sensitivity and uncertainty of the fault tree results for critical load is deduced by calculating the importance measures such as risk achievement worth, risk reduction worth, criticality importance and Fussel-Vesely importance. Finally from the results the components that are sensitive and at high risk are deduced.

LA-ICP MS Characteristic of Geochemical Composition of Veins Rocks from the Central Part of the Khibina Massive in Kola Peninsula, Northern Russia

This paper discusses the vein rocks located in the central part of Khibina Mts.. These rocks are located on the border of two zones： ore and external. In the ore, zone is present titanite-nepheline bodies whilst in the outer zone are massive-syenites ＂khibinites＂. The veins can be divided into： mikrosyenites, melteigites and other rock types （e.g., tinguaites）. The results of LA-ICP MS （laser ablation of inductively coupled plasma mass spectrometry） indicate that these rocks are associated with deep zones which formed as a result of injection of primary magma and contamination of fluids during migration, where there have hydrothermal processes. Rock-forming minerals, their corrosion and accessory minerals indicate these processes, too.

Pure Jatropha Oil for Power Generation on Floreana IslandlGalapagos： Four Years Experience on Engine Operation and Fuel Quality

In the small country of Ecuador, all environmental risks of the production and consumption of fossil fuels can be observed by damages through oil exploration in the amazonite rainforest and two tank ship accidents close by Galapagos Islands causing death of 10,000 marine iguanas and other species. Now Ecuador plans to replace all environmentally dangerous diesel generators from all four inhabited Galapagos Islands by a hybrid system using 100% renewable energy for electricity production. Since 2010 a hybrid system of two Jatropha oil generators with an electrical power of 69 kW （kWel） and a photovoltaic plant with an electrical peak power of 21 kW （kWpeak） is successfully providing electricity from renewable energy for inhabitants and tourists of Floreana Island. After more than 15.000 engine operation hours of each engine there is no engine defect. For fuel supply, the so-called ＂Living Fence＂ concept collecting Jatropha seeds by farmers and families from already existing 6,000 km hedges on Ecuadorian mainland was chosen to comply with highest biofuel sustainability standards. The Jatropha oil is produced in a decentralized so-called CompacTropha oil mill container following the ambitious German fuel quality standard DIN51605. Since 2010 Floreana project successfully demonstrates that it is possible to replace diesel gen sets by generators fueled with pure Jatropha oil from decentralized sustainable production.

Development of an Intelligent Voltage Control System for Jeju Island Power System in Korea

As the voltage has local characteristics in a power system, system voltage control has depended on human experts in distribution substation local reactive power control station so far in Korea. Since coordinative automatic control has been possible due to the recent advances in computers and communication networks, the hierarchical voltage control system, consisting of primary, secondary, and tertiary control, has been applied in several European countries. Recently the Korea power system has been operated more closely to stability limits because of rapid growth in load-demand as seen in Europe. For this reasons, Korea electric power corporation recognized the need of the voltage control system and developed the voltage control system. This paper presents an intelligent voltage control system for domestic power system using numerical algorithm based on the sensitivity matrix and the expert system. Dynamic characteristics of the developed system are investigated using EMTDC （electromagnetic transient DC analysis program） and RTDS （real time digital simulator）. Several case studies showed the promising performance.

Power Electronic Interface with Islanding Detection and Unbalanced Fault Ride-through Capability

Power electronic interface of dispersed generation plays a very important role in connecting a dispersed generation with utility grids. A power electronic interface not only adjusts the amount of active and reactive power injecting into a grid but also implements other importance duties as well. In this study, negative-sequence current injection has been fulfilled in three-phase power electronic interface for two important duties besides injecting reference power into utility grids. The first one is for islanding detection, and the other one is to enhance unbalance-fault ride-through capability of dispersed generation. This paper introduces a mechanism of negative-sequence injection based on controlling two separate coordinates of dq-control and explains the effect of negative-sequence injection in limiting the unbalanced currents generated from a dispersed generation. Using adaptive notch filter as a signal processing unit for the three-phase system, negative-sequence components are observed. The performance of entire control system is evaluated by time domain simulations, PSCAD/EMTDC （power systems computer aided design/electromagnetic transients including DC）.

Effects of electroacupuncture on glycometabolism in metabolism syndrome

Objec ve To observe the effi cacy of electroacupuncture on glycometabolism disturbance in metabolism syndrome. Methods With matched-pairs design,80 pa ents mee ng with the diagnos c criteria for glycometabolism abnormali es were randomized into the group combining acupuncture and medica on（group A） and the western medicine group（group B）,and 40 pa ents were included in each group. Electroacupuncture was carried out on back-shu points,Zúsānlǐ（足三里 ST 36）,Zhōngwǎn（中脘 CV 12）,Sānyīnjiāo（三阴交 SP 6） and other acupoints for group A,needles were retained for 20 min except back-shu points,once a day,con nuous ten mes as a treatment course,the next treatment course was started a er an interval for 3–5 days,and totally 3 treatment courses were carried out; furthermore,the pa ents were orally administered with Glucotrol XL and felodipine,5 mg each,once a day. The pa ents in group B were treated simply with drugs（the medica on was the same to that for the group A）. Body mass index（BMI）,related biochemical indices and blood pressure of the pa ents were measured before and a er the interven on,respec vely. Results BMI,blood-fas ng glucose,blood glucose 2 h after meal,fasting insulin,insulin resistance index,systolic pressure and diastolic pressure in group A all significantly improved in comparison to those before the electroacupuncture intervention（P0.01）. The difference in BMI in group B before and after the treatments was not statistically significant（P0.05）,and other indices all showed significant improvements（P0.01）. The improvements in the indices as mentioned above in the group A after treatment were significantly better than those in the group B（P0.01）. Conclusion Electroacupuncture intervention can significantly reduce weight,combina on of acupuncture and medica on shows be er effi cacy in reducing blood glucose,improving insulin sensi vity and insulin resistance in comparison to simple administra on with medica ons.

Observation on Therapeutic Effects of Electroacupuncture for Obesity Polycystic Ovary Syndrome

Purpose： To observe the therapeutic effect of electroacupuncture for obesity polycystic ovary syndrome （PCOS）. Methods： Twenty-two cases of the patients with obesity PCOS were treated with electroacupuncture. Before and after the treatments, BMI and serum sex hormones were determined to compare the therapeutic effects. Results： In comparison between the patients before and after the treatments, there were significant differences （P〈0.05） in BMI and luteinizing hormone （LH）, but there was no significant difference （P〉0.05） in follicle stimulating hormone （FSH） and testosterone （T）. Conclusion： The therapeutic effect in electroacupuncture is obvious in lowering BMI and LH levels in PCOS patients, indicating that electroacupuncture is a new method in Chinese medicine for obesity PCOS.